Acceleration enrichment signalling means for electronic fuel systems

ABSTRACT

An acceleration enrichment signalling means for a fuel system used to supply fuel to an internal combustion engine in which the additional fuel requirement signal is generated so that additional fuel may be provided to the engine before air flow to the engine increases. The present invention provides mechanical and electrical means for working in combination with specialized circuitry to provide an increase in the fuel flow to the engine prior to any increase in air flow to thereby prevent any discontinuity in engine operation which may be caused by lags in fuel flow due to the electrical and mechanical characteristics of the main fuel system and of the engine.

ilnited States Patent 1 11] 3,726,261 Sauer I 51 Apr. 10, 1 973 [54]ACCELERATION ENRICHlVIENT SIGNALLING MEANS FOR Primary Examiner-LaurenceM. Goodridge ELECTRONIC FUEL SYSTEMS AttorneyRobert A. Benziger andPlante, Hartz, [75] Inventor: Rudolf G. Sauer, Ithaca, NY. Smth &Thompson [73] Assignee: The Bendix Corporation, Southfiel d, [57]ABSTRACT Mlch' An acceleration enrichment signalling means for a fuel[22] Filed: Jan- 25, 1971 system used to supply fuel to an internalcombustion [21] Appl' No; 109 278 engine in which the additional fuelrequirement signal is generated so that additional fuel may be providedto the engine before air flow to the engine increases. The [52] Cl"123/32 EA, 123/119 R, 123/140 MC present invention provides mechanicaland electrical [51] Int. Cl ..F02m 51/00 means f working in Combinationwith specialized [58] Fleld of Search 123/32, 32 EA, 1 l9, Circuitry toprovide an increase i the fuel flow to the 123/103 140 MC engine priorto any increase in air flow to thereby v prevent any discontinuity inengine operation which [56] References cued may be caused by lags infuel flow due to the electrical UNITED STATES PATENTS and mechanicalcharacteristics of the main fuel system and of the engine. 3,581,7236/1971 Scholl ..l23/32 EA 3,272,187 9/1966 Westbrook et a1. 3 Claims, 6Drawing Figures 2,361,206 10/1944 Hoppe ..l23/l03 E B14 77' ER)TEMPEIFHTURE SENSOR ELECTfiM/C TIMING PIC/(1U PAHifJI'LlJ 1 mm 3.726,261

SHEET 1 BF 3 BA TTER) TE M PEA 1? TUAE SENSOR 12) ELECTRON/C TIM/N6CONTROL '1 PIC/(UP UNIT 1 NVEN T OR.

Add 5M8! WITNESS: 4? f f gm $737k QMAW PATEi-HEU 3,726,251

SHEET 2 OF 3 INVENTOR.

ATTORN E Y ACCELERATION ENRICIIMENT SIGNALLING MEANS FOR ELECTRONIC FUELSYSTEMS CROSS-REFERENCE TO RELATED APPLICATION This invention is relatedto commonly assigned, copending application Ser. No. 109,277 filed inthe name of Todd L. Rachel on Jan. 25, 1971 titled AecelerationEnrichment Circuitry for Electronic Fuel System.

BACKGROUND OF THE PRESENT INVENTION Field of the Invention The presentinvention relates generally to the field of electrical and electronicfuel control systems. More particularly, the present invention relatesto that portion of the above noted field concerned with fuel injectionsystems for automotive type internal combustion engines. Specifically,an improved acceleration enrichment means is provided for an electronicfuel injection system adapted for automotive applications in whichmetered amounts of fuel are provided to more than one cylinder at atime.

BACKGROUND OF THE INVENTION In order to provide the smooth operationwhich the automotive operator demands from his vehicle, it has beenrecognized that some form of acceleration enrichment must be provided sothat the vehicle will promptly respond to an instantaneous change inoperational demands placed upon the engine. In those fuel systems inwhich injection of the various engine cylinders is accomplished bygrouping those cylinders and injecting different groups in sequence,there exists a need for acceleration enrichment in view of the fact thatthere will be a specific time delay between the command to accelerateand the next injection pulse when the command would becomeeffective. Inthose systems in which injection of the individual cylinders takes placein a sequential fashion, the need for acceleration enrichment is reducedbut is, however, desirable so that the engine will demonstrate a smooth,prompt response and will not produce excessive exhaust emissions.

Present acceleration enrichment systems are quite adequate to accomplishthe broad objectives of providing additional fuel to accomplish theacceleration enrichment function under the various operating conditionsencountered. However, two areas of difficulty have been encountered ineven the most sophisticated acceleration enrichment mechanism. The firstof these occurs during the range of vehicle operation characterized aslight load, i.e., when the throttle is very slightly depressed. This ismost often encountered when the vehicle is coming off the idle asforinstance initial acceleration from a stop. High engine and vehicleinertia combined with the maximum time period between successiveinjections makes it necessary that the air/fuel ratio be proper from oneinjection to the next at low engine speeds. However, when the throttleis opened to accelerate the engine, the additional available quantitiesof air cause the air/fuel ratio to become leaner. With the current trendin vehicle operation towards fuel systems which operate on the lean side(i.e., where the air to fuel ratio is in excess of about 17 to 1) thisadditional leanness would be excessive and will cause noticeablemisfiring which would increase exhaust emissions and which would begenerally unacceptable to the typical vehicle operator since it wouldmake operation of the vehicle, particularly the acceleration of thevehicle up to driving or cruising speeds, in a smooth and efficientmanner practically impossible. Secondly, even where misfiring does notoccur, the increased leanness described above will cause the vehicle tolose power to the point that a command for acceleration will produce amomentary deceleration short of misfiring.

It is, therefore, an object of the present invention to provide anacceleration enrichment mechanism and signal generating system forelectronic fuel control systems which will not cause the vehicle to losepower. It is a further object of the present invention to provide anacceleration enrichment mechanism which will provide additionalquantities of fuel to be added to air/fuel mixture prior to increase inthe air content thereof. It is a further object of the present inventionto provide an acceleration enrichment device which will cause theair/fuel ratio to become less lean during the initial phases of vehicleacceleration. It is a specific object of the present invention toprovide a signalling mechanism which will generate a command signalindicative of an acceleration demand prior to any increase in theair/fuelratio.

SUMMARY OF THE PRESENT INVENTION The present invention contemplates theaddition of a lost motion connection between the accelerator pedal andthe throttle plate. In addition, a potentiometer is coupled to theconnection between the lost motion link and the accelerator pedal tomove contemporaneously with the throttle pedal. The lost motionconnection is resiliently biased in one direction so that initialmovement of the accelerator pedal in a direction to increase vehicleair/fuel flow (and hence, speed) will cause the lost motion connectionto move prior to movement of the throttle plate. In this fashion, thepotentiometer will register a voltage change prior to movement of thethrottle plate. This voltage change will be used to signal appropriateelectronic circuitry to increase fuel flow to the injector valves of thefuel system prior to movement of the throttle plate, thus providing anincrease in fuel flow prior to the increase in air flow. Thus, thepresent invention may be characterized by the presence of a lost motionconnection between the throttle control and the throttle plate and theuse of a signal generating potentiometer coupled to the throttle controlmechanism so that changes in throttle setting will cause aninstantaneous change in potentiometer setting followed by a change inthrottle plate position a brief time later. This mechanism, whenconnected to appropriate electrical or electronic circuitry thusprovides a means for achieving acceleration enrichment providingadditional quantities of fuel prior to any increase in air to theair/fuel mixture.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic diagram of anelectronic fuel control system adapted to control delivery of anair/fuel mixture to the combustion cylinders of an internal combustionengine.

FIG. 2 shows an illustrative schematic of the acceleration enrichmentsignalling mechanism of the present invention taken along the line 2-2of FIG. 1.

FIG. 3 shows an electronic schematic diagram of a main computing circuitwith which the present invention is of utility.

FIG. 4 shows an electronic circuit adapted to interface between themechanism of FIG. 2 and the circuits ofFIGS. 3 and 5.

FIG. 5 shows an acceleration enrichment circuit useful with the presentinvention.

FIG. 6 shows an alternative embodiment of the lost motion link of FIG.2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG.1, an electronic fuel control system is shown which may utilize thepresent invention. The system is comprised of an electronic control unit10 which receives signals from a timing pick-up 12, a temperature sensor14, various parameter sensors 16 associated with a throttle body, andsignals from the acceleration enrichment signalling mechanism 18.Parameter sensors 16 and acceleration enrichment mechanism 18 areattached to throttle body 20 which controls the flow of air into theengine. Throttle body 20 has a pair of air passages passing therethroughindicated as 22 and the effective crosssectional area of passages 22 iscontrolled by throttle plates 24. Throttle plates 24 are mounted onshaft 26 for controlled rotation therewith. The angular position ofshaft 26 and hence of throttle plates 24 is controlled by throttlecontrol means comprised of actuating means in the form of pedal 28 andsuitable connecting linkage 30 through the intermediary of accelerationenrichment signalling mechanism 18.

The electronic control unit 10 is energized by battery 32 which alsoenergizes those of the various sensors which require externalenergization. The output of the electronic control unit 10 is used tocontrol the energization of an injector valve means 34 which is mountedin the intake manifold 36 and is adapted to introduce an air/fuelmixture for intake through intake valve 38, shown in an open position,into the combustion cylinder 40 of the internal combustion engine. Fuelis provided to injector valve means 34 from fuel tank 42 by means ofpump 44 and suitable fuel supply and return lines 46.

Referring now to FIG. 2, the acceleration enrichment signallingmechanism 18 of FIG. 1 is shown in an illustrative schematic form.Mechanism 18 comprises a housing member 60, lost motion link 62,resilient biasing means 64, position control means 66, signal generator68, in the form of a potentiometer, in this instance, and closing means70. Lost motion link 62 is fixedly attached to the throttle plate shaft26 to control rotation thereof. Lost motion link 62 includes a travelslot 72 and position control means 66 includes a pin member 74 mountedfor movement in the travel slot 72. Resilient means 64 are operative tourge the pin member 74 to an extreme end of slot 72 while positioncontrol means 66 are operative to urge the pin towards the other extremeend of slot 72. Closing means 70 are operative to urge the lost motionlink and, hence, the throttle plates 24, counterclockwise relative tothe drawing of FIG. 2, to effect closing movement thereof upon releaseof tension in control means 66. Signal generating means 68 is operativeto produce an output signal on signal lead 74 which is indicative of theinstantaneous position of position control means 66. Lead 74 terminatesin electrical port A and the output signal appearing thereat will bemore fully discussed hereinbelow. Alphabetic designations are usedherein to denote circuit points which are, or may be made, common to twoor more figures of the drawing. In the preferred embodiment, I haveselected a linear potentiometer 68 having its slider connected to theposition control means 66 to provide this signal. Alternatively,potentiometer 68 could be located elsewhere in the circuit where itsslider could be coupled to the control linkage 30 or the actuator 28.The potentiometer 68 receives a voltage input on lead 76 from thebattery 32- as shown in FIG. 1 and the voltage on lead 74 is thereforedirectly proportional to the position of the position control means 66.

In operation, with the throttle plate at any angular position indicativeof an engine operating situation, the application of pressure tothrottle pedal 28 will cause, through the suitable linkage 30, arightward (relative to FIG. 2) movement of position control means 66.This movement will change the instantaneous voltage appearing on lead 74and, in this embodiment, will cause that voltage to increase. However,the initial movement of the position control means 66 will cause pin 74to move rightward within slot 72 against the bias of resilient means 64prior to any movement of the throttle plates 24. This can readily bearranged by insuring that the initial increment of movement of resilientmeans 64 requires less force than does movement of the lost motion link62 against the bias of closing means and any friction present in themounting of shaft 26. Thus, the voltage on lead 74 will changeindicating a desire for acceleration prior to any movement of thethrottle plate 24.

Referring now to FIG. 3, the main computing means of the electroniccontrol unit 10 is illustrated. This circuit is shown as being energizedby a voltage supply designated by B+ at the various locations noted. Inthe application of this system to an automotive fuel control system, thevoltage supply could be the battery and/or battery charging systemconventionally used as the vehicles electric power source. The manskilled in the art will recognize that the electrical polarity of thevoltage supply, shown in FIG. 1 as battery 32, could be readilyreversed.

The circuit receives along with the voltage supply, various voltagesignal sensory inputs indicative of various operating parameters of theassociated engine. Intake manifold pressure sensor 16 (one of thesensors 16 shown in FIG. 1) supplies a voltage indicative of manifoldpressure, temperature sensor 14 is operative to vary the voltage acrossthe parallel resistance to provide a voltage signal indicative of enginetemperature and voltage signals indicative of engine speed are receivedat circuit port 102 from the timing pick-up 12. This signal may bederived from any source indicative of engine crank angle but ispreferably from the engines ignition distributor.

The circuit 100 is operative to provide two consecutive pulses, ofvariable duration, through sequential networks to circuit location 104to thereby control the on time of transistor 106. The first pulse isprovided via resistor 108 from that portion of circuit 100 having inputsindicative of engine crank angle and intake manifold pressure.Termination of this pulse initiates a second pulse which is provided viaresistor 110 from that portion of the circuit 100 having an input fromthe temperature sensor 14. These pulses received sequentially at circuitlocation 104, serve to turn transistor 106 on (that is, transistor 106is triggered into the conduction state) and a relatively low voltagesignal is present at circuit output port 112. This port may beconnected, through suitable inverters and/or amplifiers (not shown) tothe injector means (shown as 34 in FIG.

1) such that the injector means. are energized and thus open wheneverthe transistor 106. is on. Because the injector valve means arerelatively slow acting, compared with the speed of electronic devices,the successive pulses at circuit location 104 will result in theinjector valve means remaining open. until after the termination of thesecond pulse.

The duration of the first pulse is controlled by the monostablemultivibrator network associated with transistors 114 and 116. Thepresence of a pulse received via input port 102 will trigger themultivibrator into its unstable state withtransistor'ltl4 inttheconducting state and transistor 116 blocked .(or inthe nonconductingstate). The period. of time during which transistor 114 isconductingwill. be controlled. by the voltage signal from manifoldvpressure sensor 16. Conduction of transistor 114] will cause thecollector 114a thereof to assume arelatively low voltage closetotheground or common voltage. This low voltage will cause the base 118b oftransistor ll8 tolassume a low voltage below that required fortransistor 118 to be triggered into the conduction state thuscausing-transistor. 118 to be turned of Thevoltage at the collector 1180will therefore rise towards the B+ value'andwillbe communicated viaresistor 108ntocircuit location;10,4iwhere it.

will trigger transistor 106 into the on"or conduction state, thusimposing a relativelylow voltage at circuit port 112. As hereinbeforestated, the presence of a low voltage signal at circuit port 1l2willcause the selected injector valve means, toopenandremain open. When thevoltage from the manifoldpressuresensor 16 has decayed to the valuenecessaryfor the 'multivibrator to relax or return to its stablecondition,,transistor 116 will be triggered on and transistor 114 .willbe turned transistor 126v has been biased .on and, with there sistor.network 128, constitutes a second current source. Current from bothsources flows intothe base of transistor 130 thereby holdingthistransistor on. which results in a low voltage at the'collector 130a.This low voltage is communicated to the base. of transistor 106 viaresistor 110.

When transistor 114 turns off signalling termination of the first pulse,transistor 1 18 turns on and the potential at the collector 118a fallsto a low value. The current from the current source comprised oftransistor 120 and resistor network 122 now flows through the base oftransistor 120 and the capacitor 124 ceases to charge. The capacitorwill then have been charged with the polarity shown in FIG. 3 to a valuerepresentative of the duration of the first pulse. However, thepotential at the collector of transistor 120 will be only slightlypositive with respect to ground since only several pn junctions separateit from ground. This will impose a negative voltage on circuit location132 which will reverse bias diode 134 and transistor will be turned off.This will initiate a high voltage signal from the collector oftransistor 130 to circuit location 104 via resistor 110 which signalwill retrigger transistor 106 on and the second injector means controlpulse will appear at circuit port 112. The time duration between firstand second pulses will be sufficiently short so that the injector meanswill not respond to the brief lack of signal.

While the diode 134 is reversed biased, the current from the currentsource comprised of transistor 126 and resistor network 128 will beflowing through circuit location 132 and into the capacitor 124 tocharge the capacitor to the point that circuit location 132 will againbe positively biased with respect to ground. This willthen forward biasdiode 134 and transistor 130 will turn back on". This will terminate thesecond pulse and the injector valve means will subsequently close.

The duration of the second pulse will be a function of the time requiredfor circuit location 132 to become sufficiently positive for diode134-to be forward biased. This, in turn, is a function of the charge oncapacitor 124 and the magnitude of the charging current supplied by thecurrent source comprised of transistor 126 and resistor network 128. Thecharge on capacitor 124 is, of course, a function of the duration of thefirst pulse. However, the rate of charge (i.e., magnitude of thecharging current) is a function of the base voltage at transistor 126.This value is controlled by the voltage divider networks136 and 138 withthe effect of network 138 being variably controlled by the enginetemperature sensor 14.

Thecircuit of FIG. 3 contains three circuit points denoted'by alphabeticdesignations. These are circuit points C, Alternate C and E. Point'E andAlternate C are at the bases of transistors 106 and l26respectively andpoint C is located within the network which establishes the voltagelevel applied to inductive pressure sensor 16.

Referring now to FIGS. 3, 4 and 5, a circuit useful with my inventionwill be described. The circuit of FIG. 4 comprises an amplifier portion200, an analog signal generating portion 202 and a controlled switchportion 204. The amplifier portion 200 is energized by B+ as noted andreceives a signal from the acceleration enrichment signalling mechanism18 (of FIG. 1) through signal input port point A. An output signal fromamplifier 200 is coupled to analog signal generating portion 202 andcontrolled switchingportion 204 from circuit location 206 via leads 208and 210. Analog signal generating portion 202 is operative toprovide avoltage signal at circuit point C for a period of time followingreceiptof an input signal. Controlledsignal portion 204 is operative toprovide an output signal of variable duration at circuit point Dfollowing receipt of an input signal.

Amplifier portion 200 is comprised of transistor 212 and resistor 214and 216. This circuit is arranged as a common-emitter amplifier withresistor 214 being the load resistor. Thus, the voltage at the collectorterminal 2126 of transistor 212 will increase as the voltage at the baseof the transistor (in this instance, the voltage output of thepotentiometer output lead 74 and port A) decreases. Therefore, thecollector terminal voltage will represent the instantaneous positioncontrol means setting. The gain of this amplifier configuration is theratio of the resistance of resistor 214 to that of resistor 216. Byproper selection of resistive values, the switching control circuit 200,and thus the circuits 202 and 204 can be made as sensitive orinsensitive to slight throttle movements as desired.

Analog signal generating circuit 202 is comprised of capacitor 218,resistor 220, and transistor 222. The capacitor 218 interconnects thebase of transistor 222 to the output of switching control circuit 200and the resistor 220 interconnects the base of transistor 222 and theemitter of the transistor-222 and provides that, under steady stateconditions, transistor 222 will be switched off.

The emitter of transistor 222 is connected to point C. Point C may beconnected to either circuit point C or Alternate C (in FIG. 3) and,under steady state conditions will be at an electrical potentialdetermined by the circuit potential to which point C is connected andthe amount of conduction of transistor 222.

Under steady state conditions, capacitor 218 will behave as an opencircuit and resistor 220 will maintain the voltage at the base of thetransistor 222 at or below the voltage at the emitter of the transistor222. If the voltage at circuit location suddenly rises (due to a changein the base voltage indicative of an acceleration demand) the voltage atthe base of transistor 222 will rise by an equivalent amount andtransistor 222 will begin to conduct. The amount of conduction will bedetermined by the basev voltage of transistor 222 and this will bedetermined as a function of the voltage at circuit location 206 due tothe capacitive coupling and also as a function of the time period overwhich the voltage increased since the capacitor 218 will immediatelybegin to charge (or discharge) to a new steady state level.

The output signal from amplifier portion 200 is also provided tocontrolled switch 204. This circuit 204 is comprised of a capacitor 224,a bias network comprised of resistors 226, 228, 230 and 232, andemitter- .coupled pair of transistors 234 and 236, resistors 238 and 240and switching transistor 242. The bias network of resistors 226, 228,230 and 232 is arranged so that the potential at the base of transistor236 exceeds the potential at the base of transistor 234 (with respect tothe ground or common potential) therefore biasing transistor 234 on andturning transistor 236 off. The base of transistor 242 is connected tothe collector of transistor 236 so that the electrical state oftransistor 242 will coincide with the state of transistor 236. Thecollector of transistor 242 is connected to circuit point D and thepotential at D will be determined by the resistances of resistors 304,306 whenever transistor 242 is off and will be at the ground or commonpotential whenever transistor 242 is on.

The capacitor 224 functions as an open circuit under steady stateconditions and responds to voltage changes at circuit location 206 inthe same manner as does capacitor 218. The emitter-coupled pair oftransistors 234, 236 is arranged to respond only to voltage changes atcircuit location 206 which are sufficiently great that the capacitivecoupling between circuit location 206 and the base of transistor 234will raise the base voltage above the voltage at the base of transistor236 established by the voltage divider effect of resistors 230 and 232.Since the capacitor 224 will begin to charge (or discharge) immediatelyupon a voltage change at circuit location 206, the magnitude of thatvoltage change and the rate of that change will influence circuit 204.That is, if the magnitude of the change is small, or if the rate of thechange is low, the voltage at the base of transistor 234 may not changesufficiently for it to turn off and thereby cause transistors 236 and242 to turn on.

Referring now to FIG. 5, a circuit 300 is shown. Circuit 300 is adaptedto generate a single pulse of fixed duration for ultimate application tothe injector valve means most recently energized. Circuit 300 iscomprised of normally conducting transistor 302, bias establishingresistors 304 and 306, load resistors 308 and 310, zener diode 312,capacitor 314 and diode means 316.

Referring now to the operation of FIG. 4 in conjunction with thecircuits of FIGS. 3 and 5, and the mechanism of FIGS. 1 and 2, aninitial state of vehicle operation at a steady throttle setting will bepresumed. Depression of throttle 28 will cause an instantaneous movementof linkage 30 which will cause the setting of potentiometer 68 tochange. Therefore, the voltage picked off by lead 78 and appearing atcircuit point A will decrease. This initial movement will have theeffect of stressing spring 64 so that the position of throttle plate 24will initially be unchanged. The decrease in voltage signal received atthe base of transistor 212 will cause the voltage at the collectorthereof to increase by an amount representative of the change in voltageat circuit point A multiplied by the gain factor of the amplifierconfiguration. Thus, the voltage at circuit location 206 will rise. Theeffect of this increase in voltage will be applied via leads 208 and 210to the analog signal generating circuit 202 and the controlled switchcircuit 204.

This voltage change will be applied to capacitor 218 in the analogsignal generating circuit. Since the voltage appearing across acapacitor cannot change instantaneously, the voltage being applied tothe base of transistor 222 will also increase. This will have the effectof increasing the conductivity of transistor 222 and will cause thevoltage at the emitter of that transistor to increase so that thevoltage at circuit point C will also increase. This voltage may beapplied to either of the locations noted in FIG. 3 as circuit points Cand Alternate C. The effect of this voltage change will be to vary theestablished voltage levels in FIG. 3 so that the pulse length of thepulses established by that circuit will be increased by an amountproportional to the voltage change at circuit point C. This change involtage will be a function of the amount of change in the desiredthrottle control setting, i.e., the change in voltage at circuit pointA, and will also be a function of the speed with which the throttleposition has been changed since the charge on the capacitor will beginto change immediately. Thus, the magnitude of the effect produced on thecircuit 100 will be in proportion to the mag nitude of the change inthrottle position as well as the speed with which that change was made.When a new steady state position is established for the throttlesetting, the voltage at circuit location 206 will be established at somenew steady value and the charge on capacitor 218 will adjust to this newvalue. The rate of charge of the capacitor 218 will be a function of theRC time constant of the circuit 202 and will, therefore, control theamount of voltage change realized within circuit 100 and hence, themagnitude and duration of the effect imposed on circuit 100 by analogsignal generating circuit 202. The result of this will be a lengtheningof one or both of the injection command pulses appearing at circuit port112 (of FIG. 1). The amount of pulse duration increase will thereaftershorten as a function of the RC time constant of circuit 202 and thevoltage at circuit location 206 (i.e., as a function of the total changeand speed of change of throttle control setting). This circuit 202 will,therefore, provide for additional fuel for acceleration in an amountwhich varies approximately as engine need for enrichment varies.

The change in throttle position and, hence, the voltage at circuitlocation 206 will also be experienced by capacitor 224. This will havethe effect of increasing the voltage at the base of transistor 234. Ifthe throttle position change is of sufficient magnitude, the voltage atthe base of transistor 234 will rise above that at the base oftransistor 236 and, due to the emitter-coupled pair configuration,transistor 234 will be turned of and transistor 236 will be turned on.Conduction of transistor 236 will cause current to flow through resistor240 so that a voltage drop is experienced thereacross. This voltagedifference will be applied to the emitter-base junction of transistor242 causing that transistor to begin to conduct so that a ground, orcommon, potential signal will be experienced at circuit point D. Circuitpoint D is connected to the input point D of circuit 300 in FIG. 5 andthe presence of this ground potential will terminate current flowthrough resistor 206 so as to cause transistor 302 to be turned off.This will cause the voltage applied to capacitor 314 to increase rapidlyand this increase will be applied by way of the diode means 316 tocircuit point B. Circuit point B is connected directly to controltransistor 106 so that the presence of a signal at point E will causetransistor 106 to go into conduction, and an output signal will berealized at circuit port 112. This signal will directly control theenergization of the injector valve means 34 currently electricallycoupled to circuit port 112 (of FIG. 1). The magnitude of this signalwill be a function of the time required to discharge capacitor 314 tothe proper level and may, therefore, be established as a constant value.

Referring now to FIG. 6, an alternative form of the lost motion link isillustrated having slot 172 and pin 174 slidingly received therein. Theresilient biasing means 167 is mounted to one side of the lost motionlink 162. It is thus out of linewith pivot 26 and its effect will,therefore, be somewhat different than the effect of that shown in FIG. 2embodiment.

While a preferred embodiment of the invention has been disclosed, itwill be apparent to those skilled in the art that changes may be made tothe invention as set forth in the appended claims, and, in some cases,certain features of the invention may be used to advantage withoutcorresponding use of other features. Accordingly, it is intended thatthe illustrative and descriptive materials herein be used to illustratethe principles of the invention and not to limit the scope thereof.

1 claim:

1. In a fuel control system of the type having elec- -tronic circuitryto generate electrical signals for controlling actuation of injectorvalve means to thereby control fuel delivery to an internal combustionengine having a throttle-valve controlled air intake and meansexternally positionable by an operator controlled linkage mechanism tovariabley control the throttle valve position, the improvementcomprising means providing a lost-motion mechanical connection betweenthe throttle valve and the operator positionable throttle valve controllinkage, resilient means for biasing the lost-motion connection towardsone extreme position corresponding to the positon assumed in the absenceof an operator signal, and resistive electrical signal generating meansconnected to the operator positionable throttle valve control linkageoperative to generate an electrical signal indicative of theinstantaneous throttle valve control linkage setting whereby openingmovement of the throttle valve control linkage will cause a change inthe generated electrical signal in synchronism with the motion of thethrottle valve control linkage and prior to a change in the throttlevalve positon and means for communicating said electrical signal to theelectronic circuitry for controllably altering the injector valve meansactuation whereby fuel delivery may be increased prior to increases inair flow through the air intake means.

2. The system as claimed in claim 1 wherein said signal generating meanscomprise resistive potentiometer means having a wiper arm porton and acontact member and said wiper arm portion is coupled to said throttlecontrol means and said contact member is moved in response to said wiperarm portion to provide a variable voltage signal indicative of saidwiper arm portion position.

3. An air intake throttle control for internal combustion engines foruse with electronic fuel control systems comprising:

a throttle body adapted to be attached to the air intake of the engine;

throttle valve means within said body positionable to control air flowtherethrough;

throttle valve position control means coupled to said throttle valvemeans responsive to an operator signal operative to variably positionsaid throttle valve means within said throttle body;

said throttle valve position control means including a lost-motionlinkage member whereby motion of said throttle valve position controlmeans may precede a change in the position of said throttle valve meansrelative to said throttle body; and

electrical means including a resistive element connected to saidthrottle valve position control means such that the lost-motion linkagemember is interposed between the electrical means and the communicatingsaid electrical signal to the elecihfome Valve means 581d electricalmeans tronic fuel control system whereby fuel delivery to cooperativewith the lost-motion member to product an electrical signal indicativeof a movement commended by the operator prior to the 5 movement of thethrottle valve means said electrical means further including means forthe engine may be increased in response to said electrical signal priorto an increase in air flow through said throttle body.

1. In a fuel control system of the type having electronic circuitry togenerate electrical signals for controlling actuation of injector valvemeans to thereby control fuel delivery to an internal combustion enginehaving a throttle-valve controlled air intake and means externallypositionable by an operator controlled linkage mechanism to variableycontrol the throttle valve position, the improvement comprising meansproviding a lost-motion mechanical connection between the throttle valveand the operator positionable throttle valve control linkage, resilientmeans for biasing the lost-motion connection towards one extremeposition corresponding to the positon assumed in the absence of anoperator signal, and resistive electrical signal generating meansconnected to the operator positionable throttle valve control linkageoperative to generate an electrical signal indicative of theinstantaneous throttle valve control linkage setting whereby openingmovement of the throttle valve control linkage will cause a change inthe generated electrical signal in synchronism with the motion of thethrottle valve control linkage and prior to a change in the throttlevalve positon and means for communicating said electrical signal to theelectronic circuitry for controllably altering the injector valve meansactuation whereby fuel delivery may be increased prior to increases inair flow through the air intake means.
 2. The system as claimed in claim1 wherein said signal generating means comprise resistive potentiometermeans having a wiper arm porton and a contact member and said wiper armportion is coupled to said throttle control means and said contactmember is moved in response to said wiper arm portion to provide avariable voltage signal indicative of said wiper arm portion position.3. An air intake throttle control for internal combustion engines foruse with electronic fuel control systems comprising: a throttle bodyadapted to be attached to the air intake of the engine; throttle valvemeans within said body positionable to control air flow therethrough;throttle valve position control means coupled to said throttle valvemeans responsive to an operator signal operative to variably positionsaid throttle valve means within said throttle body; said throttle valveposition control means including a lost-motion linkage member wherebymotion of said throttle valve position control means may precede achange in the position of said throttle valve means relative to saidthrottle body; and electrical means including a resistive elementconnected to said throttle valve position control means such that thelost-motion linkage member is interposed between the electrical meansand the throttle valve means, said electrical means cooperative with thelost-motion member to product an electrical signal indicative of amovement commended by the operator prior to the movement of the throttlevalve means ; said electrical means further including means forcommunicating said electrical signal to the electronic fuel controlsystem whereby fuel delivery to the engine may be increased in responseto said electrical signal prior to an increase in air flow through saidthrottle body.